I know - repeating the importance of water getting to the roots of the roses is getting tiresome! Judging from the majority of queries I receive or view on social media, it still often is the reason why the roses are not performing well.
With the relatively good rains we experienced from December to April and the in-between irrigation, our mother plant bushes have grown tremendously dense and tall. So dense, that spraying with Chronos to prevent black spot defoliation could not penetrate and cover the leaves on all sides and in the centre.
Here one can clearly see that where Chronos does come into contact with the leaves, is most certainly does prevent or limit defoliation.
The Chronos spray did not reach the base of the plants, consequently they are defoliated.
Inspect your roses
Rose bushes that are looking pretty poor with no new growth will benefit from some closer inspection. Dig one or two inspection holes (about 30cm deep) next to the bush. From this you will be able to decide whether it suffices to deeply re-dig around the bushes, introducing a lot of compost even with dried up autumn leaves, peanut shells or similar organic material.
This will ensure better water penetration and aeration. In the case of severe root competition, it means digging up nearby smaller plants, shrubs and perennials or lifting the roses and re-planting the rose in a better open spot or planting it in a large pot and sinking it into the soil at the same spot.
The continued watering of the roses from now until pruning time depends largely on the condition of the roses. If there are still new shoots and flower buds, watering at least once a week will let the rose flower into winter.
If there is no sign of new leaves on the roses, water can be gradually withdrawn from the bushes. Water once more this month and again mid-June. However, if they are under irrigation and especially if annuals or vegetables have been underplanted they do not mind receiving water much more frequently.
Fertilising NOW would only make sense in Durban in order to extend the flowering into August.
Bushes that are still flowering well should be sprayed fortnightly into June.
To prune or not to prune?
Rose bushes that are defoliated and are not doing well, or that might be in the way of your vegetables, can be slightly trimmed, however, it is not a good idea to prune them right down.
They would then be encouraged to sprout, but during the short-day period, such new shoots would be blind. Meaning they would not be able to form a flowering bud in the tip of such new shoots.
Sprouting after defoliation, the new shoots will all be blind.Don't prune these bushes until July.